Soil Testing For Sustainable Farming

Proper soil testing is essential for sustainable farming systems. However, debate in the media seems to focus on accuracy and methods. Of course these are important considerations, but an even more important one is usually overlooked.

The problem is that the traditional view has been that soil fertility (and hence farm productivity) is based on achieving some sort of optimum balance of plant nutrients. Of course, soil is so much more than just a nutrient sponge for plants to suck stuff out of. For this reason, it is important to also assess the physical and biological attributes of the soil - relative to the requirements of the chosen land use.

This is especially true for highly specialized land uses such as Truffle production. Both the host trees and the fungus are widely distributed throughout Europe, but truffles are only found in specific parts of France and Italy. Here it seems, conditions are such that the only way for either the tree or fungus to survive is in a symbiotic association where each supports the other.

Lessons learned from studying situations like this have revealed that soil management for sustainable farming is a more involved process than simply working out how much fertilizer to use.

Research has actually shown that the most important criterion for productive soil is the relative proportions of five important elements. The problem in the past (with things like the Albrecht System) has been in viewing these elements simply as plant nutrients, when in fact their most important function is in determining physical soil attributes. That is, things like friability, the ability to drain freely while still retaining moisture needed for plant growth, etc.

The elements involved all have a positive charge and include Calcium, Magnesium, Sodium, Potassium and Hydrogen. Their proportions need to be determined relative to the capacity of any soil to hold them and also on the amount of Organic Carbon present.

Another important consideration is that during the process of optimizing this balance relationship, the plant available levels of the important mineral nutrients will often change. This means that repeat tests will be needed over a number of years until the soil settles into a stable state in which more sustainable practices can be effectively achieved.

To ensure you can properly maintain sustainable practices on your farm, there are two soil tests to choose from:

• Black Truffle Soil Testing - Specifically for production to Tuber melanosporum in a cultivated Truffière.
• Sustainable Farming Soil Tests - Pasture, Nut groves and other tree crops, agro-forestry and permaculture - where soil function is of critical importance.

Soil testing for more conventional land uses like pasture will naturally include plant nutrient levels and fertilizer recommendations. However the analysis system we use focus first and foremost on the physical condition of the soil. This is important for aeration, drainage, root access, nutrient availability and the health of the biological community in the soil. It is only really after the soil condition has been optimized that fertilizer recommendations become effective for sustainable production.

Truffles are, of course, a special case. The Truffle soil test we use is farm more extensive than anything that would be required for other land uses. While the physical condition of the soil is also important here, it will be very different from what many people would expect. This is because the aim is to redefine the entire soil ecosystem to one that both protect the tree-fungus symbiosis and lead to the production of truffles. We still have much to learn about this production system, but here is a test that will ensure you benefit from the latest research available.